The present invention relates to an apparatus for actuating at least one outlet valve of a valve-controlled internal combustion engine for motor vehicles.
It is known, for example, from US 2010/319657 A1 to increase the braking action of an internal combustion engine in the overrun mode by superimposing a decompression action on the exhaust-gas backpressure by means of a pressure flap in the exhaust-gas section (EVB or exhaust valve brake), in which at least one outlet valve per cylinder of the internal combustion engine is held open in an intermediate position in the braking mode. This takes place in the valve train of the internal combustion engine by means of a hydraulically loaded piston/cylinder unit in the force flow between the driving cam of the camshaft and the actuating element which loads the outlet valve, or a rocker arm. Furthermore, a second piston/cylinder unit is arranged in the actuating element, which second piston/cylinder unit is designed as a hydraulic valve-play compensation element (HVC) which is known per se.